JP2552861B2

JP2552861B2 - Zoom lens

Info

Publication number: JP2552861B2
Application number: JP62126979A
Authority: JP
Inventors: 博文槌田
Original assignee: Olympus Optical Co Ltd
Current assignee: Olympus Corp
Priority date: 1987-05-26
Filing date: 1987-05-26
Publication date: 1996-11-13
Anticipated expiration: 2011-11-13
Also published as: JPS63292106A

Description

【発明の詳細な説明】〔産業上の利用分野〕本発明は、カメラ特に電子スチルカメラの変倍可能な
レンズ系に関するものである。The present invention relates to a variable magnification lens system for a camera, in particular for an electronic still camera.

[Conventional technology]

CCD等の固体撮像素子を用いたビデオカメラは、半導
体技術などの急速な発達に伴つて今後ますます普及して
いくのものと思われる。なかでも電子スチルカメラは、
その即時性などから現在の銀塩カメラにとつて代わるも
のとして期待されている。Video cameras using solid-state imaging devices such as CCDs are expected to become more popular in the future with the rapid development of semiconductor technology. Among them, the electronic still camera
Due to its immediacy, it is expected to replace the current silver halide cameras.

一眼レフ式の電子スチルカメラを考えた場合、その撮
影レンズには長いバツクフオーカスが要求される。それ
は、撮影レンズと撮像素子との間にフアインダー分割ミ
ラー，水晶ローパスフイルター，赤外カツトフイルター
などの光学部材を配置しなければならないためである。When considering a single-lens reflex type electronic still camera, a long back focus is required for the taking lens. This is because optical members such as a finder dividing mirror, a crystal low-pass filter, and an infrared cut filter must be arranged between the taking lens and the image sensor.

例えば2/3インチサイズの撮像素子の場合、クイツク
リターン方式では25mm程度、ガラスブロツクよりなるハ
ーフミラー方式でも20mm程度の長いバツクフオーカス
（空気換算）が要求される。したがつて電子スチルカメ
ラ用レンズにおいては特に短い焦点距離のレンズつまり
広角レンズではレンズ構成が複雑なものになる。さらに
変倍を行なうようにしたり大口径にしたりすると少ない
レンズでの構成とすることは困難になる。For example, in the case of a 2/3 inch size image pickup device, a long back focus (air conversion) of about 25 mm is required for the quick return method and about 20 mm for the half mirror method of a glass block. Therefore, in the lens for the electronic still camera, the lens configuration becomes complicated especially for a lens having a short focal length, that is, a wide-angle lens. Further, if the magnification is changed or the diameter is increased, it becomes difficult to configure the lens with a small number of lenses.

[Problems to be solved by the invention]

本発明の目的は、変倍比が２程度、口径比がF/1.8〜F
/3.4程度、広角端での画角（２ω）が60゜〜77゜程度で
あつて広角端での焦点距離の2.0〜2.7程度の長いバツク
フオーカスを有していてかつコンパクトな変倍レンズを
提供することにある。The object of the present invention is to have a variable power ratio of about 2 and an aperture ratio of F / 1.8 to F.
/3.4, the angle of view (2ω) at the wide-angle end is about 60 ° -77 °, and the focal length at the wide-angle end is about 2.0-2.7. To do.

[Means for solving problems]

本発明の変倍レンズは、物体側より順に全体として負
の屈折力を持ち変倍時に固定でフオーカシング機能を有
することのできる第１レンズ群と、全体として正の屈折
力を持つ第２レンズ群と、全体として正の屈折力を持つ
第３レンズ群とよりなり、第２レンズ群と第３レンズ群
をそれらレンズ群間の相対的間隔を変化させながら移動
させることによつて像位置を一定に保つたまま変倍を行
なうことを特徴としたレンズ系である。The variable power lens of the present invention has a first lens group having a negative refracting power as a whole from the object side and having a fixed focusing function at the time of zooming, and a second lens group having a positive refracting power as a whole. And a third lens group having a positive refracting power as a whole, the image position is fixed by moving the second lens group and the third lens group while changing the relative distance between the lens groups. This is a lens system that is characterized by performing zooming while keeping at.

現在銀塩カメラの一眼レフ用広角ズームレンズは、負
の屈折力を持つ第１レンズ群と、正の屈折力を持つ第２
レンズ群とよりなりそれらレンズ群間の相対的間隔を変
化させてズーミングを行なういわゆる２群ズームレンズ
が一般的である。この２群ズームレンズは、高変倍率化
には向かないが画角を広くとれる上にバツクフオーカス
が長いという特徴を有している。しかし２群ズームレン
ズは、ズーミング時に第１レンズ群が移動するために全
長が大きく変化する。又フオーカシング時には、可動の
レンズ群をさらに繰り出すことになり、可動のための機
構が複雑になる。そのうち、第１レンズ群は、一般に大
きくて重いためにフオーカシングの負荷も大きくなつて
しまう。Currently, wide-angle zoom lenses for single-lens reflex cameras for silver halide cameras have a first lens group having a negative refractive power and a second lens group having a positive refractive power.
A so-called two-group zoom lens, which is composed of lens groups and changes the relative distance between the lens groups to perform zooming, is generally used. This two-group zoom lens is not suitable for high zoom ratio, but has a feature that it can have a wide angle of view and a long back focus. However, the total length of the two-group zoom lens changes greatly because the first lens group moves during zooming. Further, during focusing, the movable lens group is further extended, and the mechanism for movement becomes complicated. Of these, the first lens group is generally large and heavy, so that the focusing load also increases.

本発明の変倍レンズは、変倍時に第１レンズ群を固定
してレンズ系の全長が変化しないようにするために、レ
ンズ系全体を負，正，正の三つのレンズ群により構成
し、負の第１レンズ群にて出来た虚像を第２レンズ群，
第３レンズ群により物点と像点の間の距離が変化しない
ようにリレーする方式を採用した。In the variable power lens of the present invention, in order to fix the first lens group during zooming so that the total length of the lens system does not change, the entire lens system is composed of three negative, positive, and positive lens groups, The virtual image created by the negative first lens group is
A relay system is adopted so that the distance between the object point and the image point does not change by the third lens group.

又本発明の変倍レンズは、負，正，正の三つのレンズ
群にて構成したことによつて、レンズ系全体がレトロフ
オーカス型レンズのパワー配置になり、バツクフオーカ
スを長くすることが容易になつた。Further, since the variable power lens of the present invention is composed of three lens groups of negative, positive and positive, the entire lens system has the power arrangement of the retro focus lens and the back focus can be easily lengthened. It became.

しかし上記のような構成にすることによつて、レンズ
系の非対象性は増大し、歪曲収差、非点収差などの非対
称収差は発生し易くなる。However, with the above configuration, the asymmetry of the lens system is increased, and asymmetrical aberrations such as distortion and astigmatism are likely to occur.

本発明ズームレンズにおいてこれらの収差を補正する
ためには次の条件を満足することが望ましい。In order to correct these aberrations in the zoom lens of the present invention, it is desirable to satisfy the following conditions.

（１） −0.54＜β_{II III}＜−0.1 ただしβ_{II III}は広角端における第２レンズ群，第３
レンズ群の合成の結像倍率である。(1) −0.54 <β _{II III} <−0.1 where β _{II III} is the second lens group at the wide-angle end, the third
It is a composite imaging magnification of the lens groups.

この条件（１）は広角端において、第１レンズ群によ
りできた虚像をリレーして結像させる時の結像倍率を規
定したものである。この条件（１）の上限を越えるとそ
れに伴つて第１レンズ群の負のパワーが大になり、負の
歪曲収差，非点収差およびコマ収差が増大して好ましく
ない。条件（１）の下限を越えるとレンズ系のバツクフ
オーカスを長くとることが困難になる。This condition (1) defines the imaging magnification when the virtual image formed by the first lens group is relayed and imaged at the wide-angle end. If the upper limit of this condition (1) is exceeded, the negative power of the first lens group will increase accordingly, and negative distortion, astigmatism, and coma will increase, which is undesirable. When the value goes below the lower limit of the condition (1), it becomes difficult to keep the back focus of the lens system long.

本発明のレンズ系において更に次の条件（２）〜条件
（５）を満足するようにすることが望ましい。In the lens system of the present invention, it is desirable to further satisfy the following conditions (2) to (5).

（２） 0.1＜|f_W/f_I|＜１（３） 0.1＜|f_W/f_{II III}｜＜１（４） ν_{III p}＞40 （５） 0.2＜f_W/r_{I n}＜1.4 ただし、f_Wは広角端でのレンズ全系の焦点距離、f_Iは第
１レンズ群の焦点距離、ｆ_{II III}は第２レンズ群，第３
レンズ群の合成焦点距離、ν_{III p}は第３レンズ群中の
少なくとも一つの正レンズのアツベ数、ｒ_{I n}は第１レ
ンズ群中の少なくとも一つの負レンズの像側の面の曲率
半径である。 _{(2) 0.1 <| f W} / f I | <1 (3) 0.1 <| f W / f II III | <1 (4) ν III p> 40 (5) 0.2 <f W / r I n <1.4 Where f _W is the focal length of the entire lens system at the wide-angle end, f _I is the focal length of the first lens group, f _{II III} is the second lens group, and the third lens group
The composite focal length of the lens group, ν _{III p} is the Abbe number of at least one positive lens in the third lens group, and r _{I n} is the radius of curvature of the image-side surface of at least one negative lens in the first lens group. is there.

条件（２），（３）は、条件（１）に加えてレトロフ
オーカス型レンズのパワー配置をさらに詳しく規定した
条件である。条件（２）の下限又は条件（３）の上限を
越えるとレトロフオーカスのパワー配置が弱まりバツク
フオーカスを長くすることが困難になる。また条件
（２）の上限又は条件（３）の下限を越えるとバツクフ
オーカスは長くとることが出来るが歪曲収差，非点収差
およびコマ収差が増大し好ましくない。The conditions (2) and (3) are conditions that further specify the power arrangement of the retrofocus lens in addition to the condition (1). When the lower limit of the condition (2) or the upper limit of the condition (3) is exceeded, the power distribution of the retro focus is weakened, and it becomes difficult to lengthen the back focus. If the upper limit of the condition (2) or the lower limit of the condition (3) is exceeded, the back focus can be long, but distortion, astigmatism, and coma are increased, which is not preferable.

条件（４）は、色収差を良好に補正するための条件で
この範囲を越えると特に倍率色収差が補正不足になる。Condition (4) is a condition for satisfactorily correcting chromatic aberration, and if it exceeds this range, chromatic aberration of magnification will be insufficiently corrected.

条件（５）は第１レンズ群で発生する歪曲収差および
非点収差を小さく抑えるための条件である。条件（５）
の下限を越えると歪曲収差および非点収差が増大し、上
限を越えると該当する負レンズが半球状となり好ましく
ない。The condition (5) is a condition for suppressing distortion and astigmatism generated in the first lens group to be small. Condition (5)
If the lower limit of the above is exceeded, distortion and astigmatism increase, and if the upper limit is exceeded, the corresponding negative lens becomes hemispherical, which is not preferable.

広角端の画角（２ω）が65゜以上の広角レンズの場合
は、条件（１）〜条件（５）の範囲内にあつても歪曲収
差および非点収差を小さく抑えることが少ないレンズ枚
数では困難になる。この場合、第１レンズ群のうち少な
くとも１面を光軸から離れるにしたがつて負の屈折力が
減少するような非球面にするのが効果的である。この非
球面は光軸との交点を原点として光軸方向にｘ軸、光軸
に垂直な方向にｙ軸をとるとき次の式にて表わされるも
のである。In the case of a wide-angle lens with an angle of view (2ω) of 65 ° or more at the wide-angle end, it is possible to reduce distortion and astigmatism to a small number even if the conditions (1) to (5) are satisfied. It will be difficult. In this case, it is effective to make at least one surface of the first lens group an aspherical surface so that the negative refracting power decreases as the distance from the optical axis increases. This aspherical surface is expressed by the following formula when the x-axis is set in the optical axis direction and the y-axis is set in the direction perpendicular to the optical axis with the intersection with the optical axis as the origin.

ただしＣは基準球面の曲率、p,A_2iは係数である。 However, C is the curvature of the reference spherical surface, and p and A _2i are coefficients.

この非球面において次の条件（６）を満足することが
望ましい。It is desirable that the following condition (6) be satisfied on this aspherical surface.

（６）｜Δx_I|＜ｈ（ｙ＝y_EC）ただしΔx_Iは非球面の基準球面からの偏位量、ｈは最
大像高、ｙは光軸からの高さ、y_ECはこの面における広
角端での最大画角の主光線高である。(6) | Δx _I | <h (y = y _EC ) where Δx _I is the amount of deviation of the aspherical surface from the reference spherical surface, h is the maximum image height, y is the height from the optical axis, and y _EC is this surface. It is the chief ray height of the maximum angle of view at the wide-angle end in.

この条件（６）の範囲を越えると歪曲収差が補正過剰
となるうえコマ収差も増大し好ましくない。If the range of this condition (6) is exceeded, distortion will be overcorrected and coma will increase, which is not preferable.

またレンズ系をF/2程度以上に大口径化しようとする
と、球面収差の増大が問題になる。この球面収差を補正
するためには第２レンズ群のうち少なくとも１面を光軸
から離れるにしたがつて、正の屈折力が減少するような
非球面にするのが有効である。この第２レンズ群の非球
面も前記の式にて表わされる。Further, if the lens system is to have a large aperture of about F / 2 or more, an increase in spherical aberration becomes a problem. In order to correct this spherical aberration, it is effective to make at least one surface of the second lens group away from the optical axis so as to have an aspherical surface so that the positive refracting power decreases. The aspherical surface of the second lens group is also represented by the above equation.

この第２レンズ群に用いられる非球面は、次の条件
（７）を満足することが望ましい。It is desirable that the aspherical surface used for this second lens group satisfy the following condition (7).

（７）｜Δx_II|＜0.1h （ｙ＝y₁）ただしΔx_IIは非球面の基準面からの偏位量、ｈは最
大像高、y₁は口径比2.2のマージナル光線のこの面にお
ける光線高である。(7) | Δx _II | <0.1h (y = y ₁ ) where Δx _II is the amount of deviation from the aspherical reference surface, h is the maximum image height, and y ₁ is the marginal ray with a diameter ratio of 2.2 on this surface. The ray height is high.

この条件（７）の範囲を越えると球面収差が補正過剰
になり好ましくない。If the range of this condition (7) is exceeded, spherical aberration will be overcorrected, which is not preferable.

本発明のレンズ系は、レンズ系全体又は第１レンズ群
のみを繰り出すことによつてフオーカシングを行なうこ
とが出来るのは勿論であるが、更に第２レンズ群全体又
はその一部、もしくは第３レンズ群全体又はその一部を
繰り出すことによつてもフオーカシングを行なうことが
出来る。It goes without saying that the lens system of the present invention can perform focusing by extending the entire lens system or only the first lens group, and further, the whole or a part of the second lens group, or the third lens. Focusing can also be performed by paying out the whole group or a part thereof.

本発明の変倍レンズは、第１レンズ群を繰り出してフ
オーカシングを行なう場合、変倍してもフオーカシング
の際の繰り出し量が変化しないという特徴があるが、繰
り出すレンズが重いことや、繰り出した時に光線がけら
れやすい欠点を有することになる。The variable magnification lens of the present invention is characterized in that when the first lens group is extended and focusing is performed, the amount of extension during focusing is unchanged even if the magnification is changed. It has a drawback that the light beam is easily eclipsed.

又第２レンズ群もしくは第３レンズ群によりフオーカ
シングを行なう場合は、繰り出すレンズが軽くフオーカ
シングの際の負荷が小さいという特徴がある。そのため
オートフオーカスにおける合焦速度を早めるには非常に
有効である。Further, when focusing is performed by the second lens group or the third lens group, there is a feature that the lens to be extended is light and the load at the time of focusing is small. Therefore, it is very effective in increasing the focusing speed in autofocus.

上記のフオーカシングのうち、第３レンズ群による場
合はこの第３レンズ群がフオーカスとコンペンセーター
とを兼ねた機能を持つと考えられる。したがつて第３レ
ンズ群を合焦情報にもとづいて独立して合焦位置まで移
動させるようにすれば、変倍時には第２レンズ群のみを
動かすだけでよい。これによつて複雑なズームカムを用
いる必要がなくなるために鏡枠の大幅なコストダウンが
可能になる。又広角時においては、第３レンズ群の繰り
出し量が小さくなるため、少しの繰り出し量でレンズ系
の第１面付近の物体にまで合焦させることが出来、それ
に伴なう収差変動も少なくし得る。In the above focusing, when the third lens group is used, it is considered that this third lens group has the function of both the focus and the compensator. Therefore, if the third lens group is independently moved to the in-focus position based on the in-focus information, only the second lens group needs to be moved during zooming. As a result, it is not necessary to use a complicated zoom cam, so that the cost of the lens frame can be significantly reduced. In addition, at a wide angle, since the amount of extension of the third lens group becomes small, it is possible to focus on an object near the first surface of the lens system with a little amount of extension, and the variation in aberration accompanying it can be reduced. obtain.

本発明の変倍レンズは、特に望遠端付近において軸外
下側光線によるコマフレアーが発生し易い。このコマフ
レアーを防止するためには、第１レンズ群と第２レンズ
群との間に可動のフレアー絞りを設け、このフレアー絞
りを変倍に伴なつて移動させることが有効である。In the variable power lens of the present invention, coma flare is likely to occur due to off-axis lower rays, especially near the telephoto end. In order to prevent this coma flare, it is effective to provide a movable flare diaphragm between the first lens group and the second lens group and move the flare diaphragm in accordance with zooming.

〔Example〕

次に本発明の変倍レンズの各実施例を示す。 Next, examples of the variable power lens of the present invention will be shown.

実施例１ｆ＝7.21〜14.0、F/2.0〜F/2.61 最大像高5.5、２ω＝76.2゜〜43.9゜ r₁＝515.8203 d₁＝4.0000 n₁＝1.80518 ν_１＝25.43 r₂＝−134.9555 d₂＝0.2000 r₃＝32.9979 d₃＝1.2000 n₂＝1.77250 ν_２＝49.66 r₄＝9.4782 d₄＝6.8000 r₅＝−127.6609（非球面） d₅＝8.2302 n₃＝1.49216 ν_３＝57.50 r₆＝192.2546（非球面） d₆＝D₁ r₇＝∞（フレア絞り） d₇＝D₂ r₈＝39.3143 d₈＝2.8000 n₄＝1.49216 ν_４＝57.50 r₉＝−1508.2095（非球面） d₉＝1.000 r₁₀＝∞（絞り） d₁₀＝1.0000 r₁₁＝58.7151 d₁₁＝14.3599 n₅＝1.49216 ν_５＝57.50 r₁₂＝−36.1512 d₁₂＝D₃ r₁₃＝20.9195 d₁₃＝1.4000 n₆＝1.84666 ν_６＝23.78 r₁₄＝11.1190 d₁₄＝4.6000 n₇＝1.60311 ν_７＝60.70 r₁₅＝−140.6971 非球面係数第５面Ｐ＝1.0000 A₄＝0.18197×10^-4 A₆＝0.25013×10^-6 A₈＝0.20226×10^-8 第６面Ｐ＝1.0000 A₄＝−0.61963×10^-4 A₆＝0.98435×10^-6 A₈＝−0.10510×10^-7 第９面Ｐ＝1.0000 A₄＝0.27014×10^-4 A₆＝−0.45513×10^-6 A₈＝0.60273×10^-8 ｆ 7.21 10.0 14.0 D₁ 145.77 4.113 1.000 D₂ 18.000 18.000 10.483 D₃ 1.400 11.306 17.993 バツクフオーカス 2.7f_W以上 β_{II III}＝−0.42（物点無限遠）｜Δx_I|＝0.047h,0.024h ｜Δx_II|＝0.004h |f_W/f_I|＝0.42 f_W/f_{II III}＝0.34 f_W/r_{I n}＝0.76 実施例２ｆ＝7.21〜14.0、F/2.0〜F/2.68 最大像高 5.5、２ω＝74.6゜〜43.4゜ r₁＝142.1304 d₁＝4.0000 n₁＝1.80518 ν_１＝25.43 r₂＝−193.3802 d₂＝0.2000 r₃＝36.4869 d₃＝1.2000 n₂＝1.77250 ν_２＝49.66 r₄＝9.4925 d₄＝6.9000 r₅＝−34.6204（非球面） d₅＝9.9888 n₃＝1.49216 ν_３＝57.50 r₆＝−126.0328 d₆＝D₁ r₇＝∞（フレア絞り） d₇＝D₂ r₈＝246.1865 d₈＝3.4000 n₄＝1.51633 ν_４＝64.15 r₉＝−38.4089 d₉＝1.0000 r₁₀＝∞（絞り） d₁₀＝1.0000 r₁₁＝37.2538 d₁₁＝16.1812 n₅＝1.51633 ν_５＝64.15 r₁₂＝−78.1720 d₁₂＝D₃ r₁₃＝44.2687 d₁₃＝4.6000 n₆＝1.51633 ν_６＝64.15 r₁₄＝−11.6226 d₁₄＝1.4000 n₇＝1.84666 ν_７＝23.78 r₁₅＝−21.5172 d₁₅＝D₄ r₁₆＝∞ d₁₆＝20.0000 n₈＝1.51633 ν_８＝64.15 r₁₇＝∞ 非球面係数第５面Ｐ＝1.000 A₄＝0.69337×10^-4 A₆＝−0.47807×10^-6 A₈＝0.69360×10^-8 ｆ 7.21 10.0 14.0 D₁ 14.243 4.335 1.000 D₂ 18.000 18.000 10.719 D₃ 1.400 11.610 18.637 D₄ 2.000 1.698 5.288 バツクフオーカス 2.7f_W以上 β_{II III}＝−0.43（物点無限遠）｜Δx_I|＝0.062h |f_W/f_I|＝0.43 f_W/f_{II III}＝0.32 f_W/r_{I n}＝0.76 実施例３ｆ＝7.725〜15.45、F/2.2〜F/2.83 最大像高 5.5、２ω＝69.7゜〜39.2゜ r₁＝＝171.4736 d₁＝3.6000 n₁＝1.80518 ν_１＝25.43 r₂＝−131.6160 d₂＝0.2000 r₃＝241.9195（非球面） d₃＝1.4000 n₂＝1.77250 ν_２＝49.66 r₄＝11.6488 d₄＝D₁ r₅＝∞（フレア絞り） d₅＝D₂ r₆＝∞（絞り） d₆＝1.0000 r₇＝25.0495 d₇＝23.6237 n₃＝1.49782 ν_３＝66.83 r₈＝−29.9117 d₈＝D₃ r₉＝37.6004 d₉＝4.8000 n₄＝1.58913 ν_４＝60.97 r₁₀＝−13.2100 d₁₀＝1.4000 n₅＝1.84666 ν_５＝23.78 r₁₁＝−31.5747 非球面係数第３面Ｐ＝1.0000 A₄＝0.37093×10^-4 A₆＝−0.14383×10^-6 A₈＝0.24887×10^-9 第７面Ｐ＝1.0000 A₄＝−0.17312×10^-4 A₆＝−0.14570×10^-6 A₈＝0.14601×10^-8 ｆ 7.725 11.0 15.45 D₁ 25.051 13.673 7.000 D₂ 19.000 19.000 14.354 D₃ 1.200 13.147 21.354 バツクフオーカス 2.5f_W以上 β_{II III}＝−0.39（物点無限遠）｜Δx_I|＝0.077h ｜Δx_II|＝0.004h |f_W/f_I|＝0.39 f_W/f_{II III}＝0.35 f_W/r_{I n}＝0.66 実施例４ｆ＝5.15〜10、F/2.0〜F/2.59 最大像高 4、２ω＝77.6゜〜44.5゜ r₁＝60.2284 d₁＝3.0000 n₁＝1.84666 ν_１＝23.78 r₂＝−713.8022 d₂＝0.2000 r₃＝32.0870 d₃＝1.0000 n₂＝1.77250 ν_２＝49.66 r₄＝6.9740 d₄＝5.0000 r₅＝21.4034 d₅＝1.6687 n₃＝1.49216 ν_３＝57.50 r₆＝14.9712（非球面） d₆＝D₁ r₇＝∞（フレア絞り） d₇＝D₂ r₈＝∞（絞り） d₈＝1.0000 r₉＝21.4652（非球面） d₉＝10.2008 n₄＝1.49216 ν_４＝57.50 r₁₀＝−14.8191 d₁₀＝D₃ r₁₁＝43.1447 d₁₁＝3.4000 n₅＝1.60311 ν_５＝60.70 r₁₂＝−8.6205 d₁₂＝1.0000 n₆＝1.84666 ν_６＝23.78 r₁₃＝−18.6232 d₁₃＝D₄ r₁₄＝∞ d₁₄＝14.5000 n₇＝1.51633 ν_７＝64.15 r₁₅＝∞ 非球面係数第６面Ｐ＝1.0000 A₄＝−0.17522×10^-3 A₆＝−0.22859×10^-5 A₈＝−0.26411×10^-7 第９面Ｐ＝1.0000 A₄＝−0.11116×10^-3 A₆＝0.18469×10^-5 A₈＝−0.60625×10^-7 ｆ 5.15 7.00 1.00 D₁ 10.641 4.524 1.000 D₂ 12.000 12.000 8.484 D₃ 1.200 7.744 12.91 D₄ 2.000 1.573 3.447 バツクフオーカス 2.7f_W以上Ｂ_{I II}＝−0.42（物点無限遠）｜Δx_I|＝0.062h ｜Δx_II|＝0.006h |f_W/f_I|＝0.42 f_W/f_{II III}＝0.37 f_W/r_{I n}＝0.74 実施例５ｆ＝5.15〜10.00、F/1.8〜F/2.35 最大像高 4、２ω＝77.6゜〜44.5゜ r₁＝−119.4303 d₁＝3.0000 n₁＝1.84666 ν_１＝23.78 r₂＝−59.7638 d₂＝0.2000 r₃＝21.6844 d₃＝1.0000 n₂＝1.77250 ν_２＝49.66 r₄＝6.4973 d₄＝3.1000 r₅＝8.7281 d₅＝2.2000 n₃＝1.49216 ν_３＝57.50 r₆＝7.8576（非球面） d₆＝D₁ r₇＝∞（フレア絞り） d₇＝D₂ R₈＝∞（絞り） d₈＝1.0000 r₉＝21.9148（非球面） d₉＝15.8582 n₄＝1.49216 ν_４＝57.50 r₁₀＝−14.7387 d₁₀＝D₃ R₁₁＝35.5720 d₁₁＝3.4000 n₅＝1.65160 ν_５＝58.52 r₁₂＝−9.4512 d₁₂＝1.0000 n₆＝1.84666 ν_６＝23.78 r₁₃＝−24.9449 非球面係数第６面Ｐ＝1.0000 A₄＝−0.34810×10^-3 A₆＝−0.47538×10^-5 A₈＝−0.13729×10^-6 第９面Ｐ＝1.000 A₄＝0.91907×10^-4 A₆＝−0.11386×10^-5 A₈＝0.49955×10^-8 ｆ 5.15 7.00 10.00 D₁ 10.847 4.385 2.8000 D₂ 12.000 12.000 6.073 D₃ 1.000 7.665 12.811 バツクフオーカス 2.7f_W以上 β_{II III}＝−0.42（物点無限遠）｜Δx_I|＝0.132h、｜Δx_II|＝0.006h |f_W/f_I|＝0.42、f_W/f_{II III}＝0.35 f_W/r_{I n}＝0.79 実施例６ｆ＝6.5〜13、F/2.0〜F/2.61 最大像高４２ω＝64.9゜〜34.3゜ r₁＝∞ d₁＝2.8000 n₁＝1.84666 ν_１＝23.78 r₂＝−186.6597（非球面） d₂＝0.2000 r₃＝66.8686 d₃＝1.2000 n₂＝1.77250 ν_２＝49.66 r₄＝10.6748 d₄＝D₁ R₅＝∞（フレア絞り） d₅＝D₂ r₆＝∞（絞り） d₆＝1.0000 r₇＝19.5673（非球面） d₇＝17.9230 n₃＝1.51633 ν_３＝64.15 r₈＝−28.8168 d₈＝D₃ r₉＝28.8498 d₉＝4.4000 n₄＝1.60311 ν_４＝60.70 r₁₀＝−9.8731 d₁₀＝1.2000 n₅＝1.84666 ν_５＝23.78 r₁₁＝−22.7162 d₁₁＝D₄ r₁₂＝∞ d₁₂＝14.5000 n₆＝1.51633 ν_６＝64.15 r₁₃＝∞ 非球面係数第２面Ｐ＝1.0000、A₄＝−0.42691×10^-4 A₆＝0.32114×10^-6 A₈＝−0.10281×10^-8 第７面Ｐ＝1.0000、A₄＝−0.45345×10^-4 A₆＝0.13458×10^-5 A₈＝−0.31271×10^-7 ｆ 6.5 9 13 D₁ 19.074 10.631 5.0 D₂ 16 16 11.599 D₃ 1.2 10.157 18.227 D₄ 2 1.486 3.448 バツクフオーカス 2.1f_W以上Ｂ_{I II}＝−0.36（物点無限遠）｜Δx_I|＝0.044h ｜Δx_II|＝0.003h |f_W/f_I|＝0.36 f_W/f_{II III}＝0.37 f_W/r_{I n}＝0.61 実施例７ｆ＝７〜14、F/2.5〜F/3.4 最大像高４、２ω＝62.5゜〜32.4゜ r₁＝76.2558 d₁＝3.0000 n₁＝1.84666 ν_１＝23.78 r₂＝−224.4742 d₂＝0.2000 r₃＝33.0553 d₃＝1.2000 n₂＝1.77250 ν_２＝49.66 r₄＝9.1886 d₄＝D₁ r₅＝∞（フレア絞り） d₅＝D₂ r₆＝∞（絞り） d₆＝1.0000 r₇＝22.5981 d₇＝3.0000 n₃＝1.49782 ν_３＝66.83 r₈＝−33.9088 d₈＝D₃ r₉＝16.7420 d₉＝3.6000 n₄＝1.60311 ν_４＝60.70 r₁₀＝−13.1671 d₁₀＝0.2000 r₁₁＝−12.0755 d₁₁＝1.2000 n₅＝1.84666 ν_５＝23.78 r₁₂＝−34.5814 ｆ 7 10 14 D₁ 20.254 10.279 6 D₂ 17 17 11.983 D₃ 1 11.043 18.881 バツクフオーカス 2.0f_W以上 β_{II III}−0.30（物点無限遠） |f_W/f_I|＝0.30、f_W/f_{II III}＝0.49 f_W/r_{I n}＝0.76 実施例８ｆ＝７〜14、F/2.2〜F/3.03 最大像４２ω＝60.2゜〜3.17゜ r₁＝28.7915（非球面） d₁＝1.2000 n₁＝1.49216 ν_１＝57.50 r₂＝8.5110 d₂＝D₁ r₃＝∞（フレア絞り） d₃＝D₂ r₄＝∞（絞り） d₄＝1.0000 r₅＝19.4891（非球面） d₅＝3.4000 n₂＝1.49216 ν_２＝57.50 r₆＝−48.0381 d₆＝D₃ R₇＝17.1091 d₇＝4.8000 n₃＝1.48749 ν_３＝70.20 r₈＝−8.6559 d₈＝1.2000 n₄＝1.78472 ν_４＝25.68 r₉＝−17.8838 非球面係数第１面Ｐ＝1.0000、A₄＝0.10368×10^-3 A₆＝−0.66880×10^-6 A₈＝0.57685×10^-8 第５面Ｐ＝1.0000、A₄＝0.69872×10^-5 A₆＝−0.83640×10^-6 A₈＝0.16132×10^-7 ｆ 7 10 14 D₁ 23.191 12.797 7 D₂ 17 17 12.973 D₃ 1.2 11.96 20.755 バツクフオーカス 2.0f_W以上 β_{II III}＝−0.28（物点無限遠）｜Δx_I|＝0.267h、｜Δx_II|＝0.0002h |f_W/f_I|＝0.28、f_W/f_{II III}＝0.46 f_W/r_{I n}＝0.82 ただしr₁,r₂,…はレンズ各面の曲率半径、d₁,d₂,…は
各レンズの肉厚およびレンズ間隔、n₁,n₂,…は各レンズ
屈折率、ν₁,ν₂,…は各レンズのアツベ数である。Example 1 f = 7.21 to 14.0, F / 2.0 to F / 2.61 Maximum image height 5.5, 2ω = 76.2 ° to 43.9 ° r ₁ = 515.8203 d ₁ = 4.0000 n ₁ = 1.80518 ν ₁ = 25.43 r ₂ = -134.9555 d _{_{2 = 0.2000 r 3 = 32.9979 d}} 3 = 1.2000 n 2 = 1.77250 ν 2 = 49.66 r 4 = 9.4782 d 4 = 6.8000 r 5 = -127.6609 ( _{_{aspherical) d 5 = 8.2302 n 3 =}} 1.49216 ν 3 = 57.50 r 6 = 192.2546 (aspherical surface) d ₆ = D ₁ r ₇ = ∞ (flare diaphragm) d ₇ = D ₂ r ₈ = 39.3143 d ₈ = 2.8000 n ₄ = 1.49216 ν ₄ = 57.50 r ₉ = -1508.2095 (aspherical surface) d ₉ = 1.000 r ₁₀ = ∞ _{_{(stop) d 10 = 1.0000 r 11 =}} 58.7151 d 11 = 14.3599 n 5 = 1.49216 ν 5 = 57.50 r 12 = -36.1512 d 12 = D 3 r 13 = 20.9195 d 13 = 1.4000 n 6 = 1.84666 ν ₆ ＝ 23.78 r ₁₄ = 11.1190 d ₁₄ ＝ 4.6000 n ₇ = 1.60311 ν ₇ ＝ 60.70 r ₁₅ ＝－140.6971 Aspherical surface 5th surface P ＝ 1.0000 A ₄ ＝ 0.18197 × 10 ^-4 A ₆ ＝ 0.25013 × 10 ^-6 A ₈ = 0.20226 × 10 ^-8 6th surface P = 1.0000 A ₄ ＝ −0.61963 × 10 ^-4 A ₆ = 0.98435 × 10 ^-6 A ₈ = -0.105 10 × 10 ^-7 9th surface P = 1.0000 A ₄ = 0.27014 × 10 ^-4 A ₆ ＝ −0.45513 × 10 ^-6 A ₈ ＝ 0.60273 × 10 ^-8 f 7.21 10.0 14.0 D ₁ 145.77 4.113 1.000 D ₂ 18.000 18.000 10.483 D ₃ 1.400 11.306 17.993 Buck-Focus 2.7f _W or more β _{II III} = −0.42 (infinity of object point) ｜ Δx _I | ＝ 0.047h, 0.024h ｜ Δx _II | ＝ 0.004h | f _W / f _I | ＝ 0.42 _{_{f W / f II III = 0.34}} f W / r I n = 0.76 example 2 f = 7.21~14.0, F / 2.0~F / 2.68 maximum image height 5.5,2ω = 74.6 ° ～43.4 ° r _₁ = 142.1304 d ₁ = 4.0000 n ₁ = 1.80518 ν ₁ ＝ 25.43 r ₂ ＝ −193.3802 d ₂ ＝ 0.2000 r ₃ ＝ 36.4869 d ₃ = 1.2000 n ₂ = 1.77250 ν ₂ ＝ 49.66 r ₄ ＝ 9.4925 d ₄ ＝ 6.9000 r ₅ ＝ −34.6204 (Non Spherical surface) d ₅ = 9.9888 n ₃ = 1.49216 ν ₃ = 57.50 r ₆ ＝ -126.0328 d ₆ ＝ D ₁ r ₇ ＝ ∞ (flare diaphragm) d ₇ ＝ D ₂ r ₈ ＝ 246.1865 d ₈ ＝ 3.4000 n ₄ ＝ 1.51633 ν ₄ = 64.15 r ₉ = -38.4089 d ₉ = 1.0000 r ₁₀ = ∞ (aperture) d ₁₀ = 1.0000 r ₁₁ = 37.2538 d ₁₁ = 16.1812 n ₅ = 1.51633 ν _{_{5 = 64.15 r 12 = -78.1720 d}} 12 = D 3 r 13 = 44.2687 d 13 = 4.6000 n 6 = 1.51633 ν 6 = 64.15 r 14 = -11.6226 d 14 = 1.4000 n 7 = 1.84666 ν 7 = 23.78 r 15 = - 21.5172 d ₁₅ = D ₄ r ₁₆ = ∞ d ₁₆ = 20.0000 n ₈ = 1.51633 ν ₈ = 64.15 r ₁₇ = ∞ Aspheric coefficient 5th surface P = 1.000 A ₄ = 0.69337 × 10 ^-4 A ₆ = −0.47807 × 10 ^-6 A ₈ = 0.69360 × 10 ^-8 f 7.21 10.0 14.0 D ₁ 14.243 4.335 1.000 D ₂ 18.000 18.000 10.719 D ₃ 1.400 11.610 18.637 D ₄ 2.000 1.698 5.288 Buck-Focus 2.7f _W or more β _{II III} = −0.43 (object point infinity) _{) | Δx I | = 0.062h |} f W / f I | = 0.43 f W / f II III = 0.32 f W / r I n = 0.76 example 3 f = 7.725~15.45, F / 2.2~F / 2.83 maximum Image height 5.5, 2ω = 69.7 ° to 39.2 ° r ₁ ＝＝ 171.4736 d ₁ ＝ 3.6000 n ₁ ＝ 1.80518 ν ₁ ＝ 25.43 r ₂ ＝－131.6160 d ₂ ＝ 0.2000 r ₃ ＝ 241.9195 (aspherical surface) d ₃ = 1.4000 n ₂ = 1.77250 ν ₂ ＝ 49.66 r ₄ = 11.6488 d ₄ ＝ D ₁ r ₅ ＝ ∞ (flare diaphragm) d ₅ ＝ D ₂ r ₆ ＝ ∞ (Aperture) d ₆ = 1.0000 r ₇ ＝ 25.0495 d ₇ ＝ 23.6237 n ₃ ＝ 1.49782 ν ₃ ＝ 66.83 r ₈ ＝－29.9117 d ₈ ＝ D ₃ r ₉ ＝ 37.6004 d ₉ ＝ 4.8000 n ₄ ＝ 1.58913 ν ₄ ＝ 60.97 r ₁₀ = −13.2100 d ₁₀ = 1.4000 n ₅ = 1.84666 ν ₅ ＝ 23.78 r ₁₁ ＝－31.5747 Aspherical surface 3rd surface P ＝ 1.0000 A ₄ ＝ 0.37093 × 10 ^-4 A ₆ ＝－0.14383 × 10 ^-6 A ₈ ＝ 0.24887 × 10 ^-9 7th surface P = 1.0000 A ₄ ＝ −0.17312 × 10 ^-4 A ₆ ＝ −0.14570 × 10 ^-6 A ₈ ＝ 0.14601 × 10 ^-8 f 7.725 11.0 15.45 D ₁ 25.051 13.673 7.000 D ₂ 19.000 19.000 14.354 D ₃ 1.200 13.147 21.354 Buckfuchs 2.5f _W or more β _{II III} = −0.39 (infinity of object point) ｜ Δx _I | ＝ 0.077h ｜ Δx _II | ＝ 0.004h | f _W / f _I | ＝ 0.39 f _W / f _{_{II III = 0.35 f W / r}} I n = 0.66 example 4 f = 5.15~10, F / 2.0~F / 2.59 maximum image height 4,2ω = 77.6 ° ～44.5 ° _{_{r 1 = 60.2284 d 1 = 3.0000}} n 1 _{_{= 1.84666 ν 1 = 23.78 r 2}} = -713.8022 d 2 = 0.2000 r 3 = 32.0870 d 3 = 1.0000 n 2 = 1.77250 ν 2 = 49.66 r 4 = 6.9740 d 4 _{_{5.0000 r 5 = 21.4034 d 5 =}} 1.6687 n 3 = 1.49216 ν 3 = 57.50 r 6 = 14.9712 ( _{_{_{aspherical) d 6 = D 1 r 7}}} = ∞ ( flare _{_{_{stop) d 7 = D 2 r 8}}} = ∞ ( stop) d ₈ = 1.0000 r ₉ ＝ 21.4652 (aspherical surface) d ₉ ＝ 10.2008 n ₄ = 1.49216 ν ₄ ＝ 57.50 r ₁₀ ＝ −14.8191 d ₁₀ ＝ D ₃ r ₁₁ ＝ 43.1447 d ₁₁ ＝ 3.4000 n ₅ ＝ 1.60311 ν ₅ ＝ 60.70 r ₁₂ = −8.6205 d ₁₂ = 1.0000 n ₆ = 1.84666 ν ₆ ＝ 23.78 r ₁₃ ＝ −18.6232 d ₁₃ ＝ D ₄ r ₁₄ ＝ ∞ d ₁₄ ＝ 14.5000 n ₇ ＝ 1.51633 ν ₇ ＝ 64.15 r ₁₅ ＝ ∞ Aspheric coefficient 6th surface P = 1.0000 A ₄ = −0.17522 × 10 ⁻³ A ₆ = −0.22859 × 10 ⁻⁵ A ₈ = −0.26411 × 10 ⁻⁷ 9th surface P = 1.0000 A ₄ = −0.11116 × 10 ⁻³ A ₆ ＝ 0.18 469 × 10 ^-5 A ₈ ＝ −0.60625 × 10 ^-7 f 5.15 7.00 1.00 D ₁ 10.641 4.524 1.000 D ₂ 12.000 12.000 8.484 D ₃ 1.200 7.744 12.91 D ₄ 2.000 1.573 3.447 BACK FOUCUS 2.7f _W or more B _{I II} ＝ −0.42 (Object point infinity) ｜ Δx _I | ＝ 0.062h ｜ Δx _II | ＝ 0.006h | f _W / f _I | ＝ 0.42 f _W / f _{II III} = 0. _{_{37 f W / r I n =}} 0.74 Example 5 f = 5.15~10.00, F / 1.8~F / 2.35 maximum image height 4,2ω = 77.6 ° ～44.5 ° _{_{r 1 = -119.4303 d 1 = 3.0000}} n 1 = 1.84666 v ₁ = 23.78 r ₂ = -59.7638 d ₂ = 0.2000 r ₃ = 21.6844 d ₃ = 1.0000 n ₂ = 1.77250 v ₂ = 49.66 r ₄ = 6.4973 d ₄ = 3.1000 r ₅ = 8.7281 d ₅ = 2.2000 n ₃ = 1.49216 v ₃ = 57.50 r ₆ = 7.8576 (aspherical surface) d ₆ = D ₁ r ₇ = ∞ (flare diaphragm) d ₇ = D ₂ R ₈ = ∞ (aperture) d ₈ = 1.0000 r ₉ = 21.9148 (aspherical surface) d ₉ = 15.8582 n ₄ = 1.49216 ν ₄ ＝ 57.50 r ₁₀ −14.7387 d ₁₀ ＝ D ₃ R ₁₁ ＝ 35.5720 d ₁₁ ＝ 3.4000 n ₅ ＝ 1.65160 ν ₅ ＝ 58.52 r ₁₂ ＝－9.4512 d ₁₂ = 10000 n ₆ ＝ 1.84666 ν ₆ = 23.78 r ₁₃ = -24.9449 Aspheric coefficient 6th surface P = 1.0000 A ₄ = -0.34810 x 10 ^-3 A ₆ = -0.47538 x 10 ^-5 A ₈ = -0.13729 x 10 ^-6 9th surface P = 1.000 A ₄ = 0.91907 x 10 ^-4 A ₆ = -0.11386 x 10 ^-5 A ₈ = 0.49955 x 10 ^-8 f 5.15 7.00 10.00 D ₁ 10.847 4.385 2.8000 D ₂ 12.000 12.000 6.073 D ₃ 1.000 7.665 12.811 Buck-Focus 2.7f _W or more β _{II III} = −0.42 (at object infinity) ｜ Δx _I | ＝ 0.132h, ｜ Δx _II | ＝ 0.006h | f _W / f _I | ＝ 0.42, f _W / _{_{f II III = 0.35 f W /}} r I n = 0.79 example 6 f = 6.5~13, F / 2.0~F / 2.61 maximum image height 4 2 [omega = 64.9 DEG ～34.3 ° _{_{r 1 = ∞ d 1 = 2.8000}} n 1 = 1.84666 ν ₁ ＝ 23.78 r ₂ ＝－186.6597 (aspherical surface) d ₂ ＝ 0.2000 r ₃ ＝ 66.8686 d ₃ = 1.2000 n ₂ = 1.77250 ν ₂ ＝ 49.66 r ₄ = 10.6748 d ₄ ＝ D ₁ R ₅ ＝ ∞ (flare Aperture) d ₅ = D ₂ r ₆ = ∞ (Aperture) d ₆ = 1.0000 r ₇ = 19.5673 (aspherical surface) d ₇ = 17.9230 n ₃ = 1.53163 ν ₃ = 64.15 r ₈ = −28.8168 d ₈ = D ₃ r ₉ ＝ 28.8498 d ₉ ＝ 4.4000 n ₄ ＝ 1.60311 ν ₄ ＝ 60.70 r ₁₀ ＝－9.8731 d ₁₀ = 1.2000 n ₅ ＝ 1.84666 ν ₅ ＝ 23.78 r ₁₁ ＝－22.7162 d ₁₁ ＝ D ₄ r ₁₂ ＝ ∞ d ₁₂ ＝ 14.5000 n ₆ = 1.51633 ν ₆ = 64.15 r ₁₃ = ∞ Aspheric coefficient second surface P = 1.0000, A ₄ = −0.42691 × 10 ⁻⁴ A ₆ = 0.32114 × 10 ⁻⁶ A ₈ = −0.10 28 1 × 10 ^-8 7th surface P = 1.0000, A ₄ ＝ −0.45345 × 10 ^-4 A ₆ = 0.134 58 × 10 ^-5 A ₈ ＝ −0.3127 1 × 10 ^-7 f 6.5 9 13 D ₁ 19.074 10.631 5.0 D ₂ 16 16 11.599 D ₃ 1.2 10.157 18.227 D ₄ 2 1.486 3.448 Buck-Focus 2.1f _W or more B _{I II} = −0.36 (at object infinity) ｜ Δx _I | ＝ 0.044h ｜ Δx _II | ＝ 0.003h | f _W / f _I | _{_{= 0.36 f W / f II III}} = 0.37 f W / r I n = 0.61 example 7 f = 7~14, F / 2.5~F / 3.4 maximum image height 4,2ω = 62.5 ° ～32.4 ° r ₁ = 76.2558 d ₁ = 3.0000 n ₁ = 1.84666 ν ₁ ＝ 23.78 r ₂ ＝ −224.4742 d ₂ ＝ 0.2000 r ₃ ＝ 33.0553 d ₃ = 1.2000 n ₂ = 1.77250 ν ₂ ＝ 49.66 r ₄ ＝ 9.1886 d ₄ ＝ D ₁ r ₅ = ∞ (flare _{_{_{stop) d 5 = D 2 r 6}}} = ∞ ( _{_{stop) d 6 = 1.0000 r 7 =}} 22.5981 d 7 = 3.0000 n 3 = 1.49782 ν 3 = 66.83 r 8 = -33.9088 d 8 = D 3 r 9 = 16.7420 _{_{d 9 = 3.6000 n 4 = 1.60311}} ν 4 = 60.70 r 10 = -13.1671 d 10 = 0.2000 r 11 = -12.0755 d 11 = 1.2000 n 5 = 1.84666 ν 5 = 23.78 r 12 = -34.5814 f 7 1 0 14 D ₁ 20.254 10.279 6 D ₂ 17 17 11.983 D ₃ 1 11.043 18.881 Buck-Focus 2.0f _W or more β _{II III} −0.30 (infinity of object point) | f _W / f _I | ＝ 0.30, f _W / f _{II III} ＝ _{_{0.49 f W / r I n =}} 0.76 example 8 f = 7~14, F / 2.2~F / 3.03 maximum image 4 2 [omega = 60.2 DEG ～3.17 ° r ₁ = 28.7915 (aspherical) d _₁ = 1.2000 n ₁ = 1.49216 ν ₁ = 57.50 r ₂ = 8.5110 d ₂ = D ₁ r ₃ = ∞ (flare diaphragm) d ₃ = D ₂ r ₄ = ∞ (diaphragm) d ₄ = 1.0000 r ₅ = 19.4891 (aspheric surface) d ₅ = 3.4000 n ₂ = 1.49216 ν ₂ ＝ 57.50 r ₆ ＝ −48.0381 d ₆ ＝ D ₃ R ₇ ＝ 17.1091 d ₇ ＝ 4.8000 n ₃ = 1.48749 ν ₃ ＝ 70.20 r ₈ ＝－8.6559 d ₈ = 1.2000 n ₄ ＝ 1.78472 ν ₄ ＝ 25.68 r ₉ = -17.8838 Aspheric surface coefficient 1st surface P = 1.0000, A ₄ = 0.10368 x 10 ^-3 A ₆ = -0.66 880 x 10 ^-6 A ₈ = 0.57685 x 10 ^-8 5th surface P = 1.0000, A ₄ ＝ 0.69872 × 10 ^-5 A ₆ ＝ −0.83640 × 10 ^-6 A ₈ ＝ 0.16132 × 10 ^-7 f 7 10 14 D ₁ 23.191 12.797 7 D ₂ 17 17 12.973 D ₃ 1.2 11.96 20.755 Backhoe Waste 2.0 f _W or more β _{II III} = −0.28 (infinity of object point) ｜ Δx _I | ＝ 0.267h, ｜ Δx _II | ＝ 0.0002h | f _W / f _I | ＝ 0.28, f _W / f _{II III} ＝ 0.46 f _W / r _{I n} = 0.82 where r ₁ , r ₂ , ... are the radii of curvature of each lens surface, d ₁ , d ₂ , ... are the wall thickness and lens spacing of each lens, and n ₁ , n ₂ , ... are each The refractive index of the lens, ν ₁ , ν ₂ , ... Is the Abbe number of each lens.

本発明の実施例１は、第１図に示すレンズ構成で、第
レンズ群の二つの面と第２レンズ群の一つの面に非球面
を用いてある。この実施例の無限遠物点に対するワイ
ド，スタンダード，テレの各状態における収差状況は夫
々第９図，第10図，第11図に示す通りである。また第３
レンズ群を繰り出すことによつてフオーカシングを行な
つた場合のレンズ前面から100の距離にある物点に対す
るワイド，スタンダード，テルの各状態の収差状況は夫
々第12図，第13図，第14図に示す通りである。The first embodiment of the present invention has a lens configuration shown in FIG. 1 and uses aspherical surfaces for two surfaces of the first lens group and one surface of the second lens group. The aberrations in the wide, standard, and tele states for the object point at infinity in this embodiment are as shown in FIGS. 9, 10, and 11, respectively. Also the third
Aberrations in wide, standard, and tell states for an object point at a distance of 100 from the front surface of the lens when focusing is performed by extending the lens group are shown in FIGS. 12, 13, and 14, respectively. As shown in.

実施例２は第２図に示す構成で、第１レンズ群の一つ
の面に非球面を用いている。第２図に示すガラスブロツ
クＦはフアインダー用分割プリズム，水晶ローパスフィ
ルター，赤外カツトフイルターなどの光学部材を想定し
たものである。この実施例の無限遠物点に対するワイ
ド，スタンダード，テレの各状態の収差状況は夫々第15
図，第16図，第17図に示す通りである。The second embodiment has the configuration shown in FIG. 2 and uses an aspherical surface on one surface of the first lens group. The glass block F shown in FIG. 2 is assumed to be an optical member such as a split prism for a finder, a crystal low pass filter, an infrared cut filter and the like. The aberrations in the wide, standard, and tele states with respect to the object point at infinity in this embodiment are 15th, respectively.
This is as shown in FIGS. 16, 16 and 17.

実施例３は第３図に示す構成で、非球面を第１レンズ
群に１面と第２レンズ群に１面用いている。この実施例
の無限遠物点に対するワイド，スタンダード，テレの各
状態の収差状況は夫々第18図，第19図，第20図に示す通
りである。The third embodiment has the configuration shown in FIG. 3 and uses one aspherical surface for the first lens group and one aspherical surface for the second lens group. The aberrations in the wide, standard, and tele states with respect to the object point at infinity in this embodiment are as shown in FIGS. 18, 19, and 20, respectively.

実施例４は第４図に示す構成で、非球面を第１レンズ
群に１面、第２レンズ群に１面用いている。この実施例
もレンズ系の後方に前記のような光学部材Ｆを配置する
ことを想定している。この実施例の無限遠物点に対する
収差状況は、夫々第21図，第22図，第23図の通りであ
る。Example 4 has the configuration shown in FIG. 4, and uses one aspherical surface for the first lens group and one aspherical surface for the second lens group. This embodiment also envisions disposing the optical member F as described above behind the lens system. The aberrations of this example for an object point at infinity are as shown in FIGS. 21, 22, and 23, respectively.

実施例５は第５図に示す構成で、非球面を第１レンズ
に１面と第２レンズ群に１面用いてある。The fifth embodiment has the configuration shown in FIG. 5, and uses one aspherical surface for the first lens and one aspherical surface for the second lens group.

この実施例の無限遠物点に対するワイド，スタンダー
ド，テレの各状態の収差状況は夫々第24図，第25図，第
26図の通りである。The aberrations in the wide, standard and tele states with respect to the object point at infinity in this embodiment are shown in FIGS. 24, 25 and 25, respectively.
It is as shown in Figure 26.

実施例６は第６図に示す構成で非球面を第１レンズ群
に１面と第２レンズ群に１面用いている。この実施例も
光学部材Ｆの配置を想定したものである。この実施例の
無限遠物点に対するワイド，スタンダード，テレの各状
態の収差状況は夫々第27図，第28図，第29図に示す通り
である。The sixth embodiment has the structure shown in FIG. 6 and uses one aspherical surface for the first lens group and one aspherical surface for the second lens group. This embodiment also assumes the arrangement of the optical member F. The aberrations in the wide, standard, and tele states for the object point at infinity in this embodiment are as shown in FIGS. 27, 28, and 29, respectively.

実施例７は第７図に示す構成で、非球面は用いていな
い。この実施例の無限遠物点に対するワイド，スタンダ
ード，テレの各状態の収差状況は夫々第30図，第31図，
第32図の通りである。The seventh embodiment has the structure shown in FIG. 7 and does not use an aspherical surface. Aberrations in the wide, standard and tele states with respect to the object point at infinity in this embodiment are shown in FIGS. 30, 31 and 31, respectively.
This is as shown in FIG.

実施例８は第８図に示す構成で非球面を第１レンズ群
に１面と第２レンズ群に１画用いている。この実施例の
無限遠物点に対するワイド，スタンダード，テレの各状
態の収差状況は夫々第33図，第34図，第35図に示す通り
である。Example 8 has the structure shown in FIG. 8 and uses one aspherical surface for the first lens group and one aspherical surface for the second lens group. The aberrations in the wide, standard, and tele states for the object point at infinity in this embodiment are as shown in FIGS. 33, 34, and 35, respectively.

〔The invention's effect〕

本発明の変倍レンズは、変倍非が２程度、口径比がF/
1.8〜F3.4程度、口角端での画角が77゜〜60゜程度のレ
ンズ系であつて、口角端の焦点距離の2.0〜2.7倍程度の
長いバツクフオーカスを有し、構成枚数が４〜７枚と極
めて少なく、角収差とも良好に補正されたものである。
また中玉もしくは後玉でのフオーカシングも可能であ
る。The variable power lens of the present invention has a zoom ratio of about 2 and an aperture ratio of F /
A lens system with a range of 1.8 to F3.4 and an angle of view of 77 ° to 60 ° at the corner of the mouth, having a long back focus of about 2.0 to 2.7 times the focal length of the corner of the mouth, and the number of components is 4 to 4. The number of images is as small as 7, and the angular aberration is well corrected.
It is also possible to focus on the middle or rear balls.

[Brief description of drawings]

第１図乃至第８図は夫々本発明の変倍レンズの実施例１
乃至実施例８の断面図、第９図乃至第14図は実施例１の
収差曲線図、第15図乃至第17図は実施例２の収差曲線
図、第18図乃至第20図は実施例３の収差曲線図、第21図
乃至第23図は実施例４の収差曲線図、第24図乃至第26図
は実施例５の収差曲線図、第27図乃至第29図は実施例６
の収差曲線図、第30図乃至第32図は実施例７の収差曲線
図、第33図乃至第35図は実施例８の収差曲線図である。1 to 8 show Embodiment 1 of the variable power lens of the present invention.
To 8 are sectional views, FIGS. 9 to 14 are aberration curve diagrams of Example 1, FIGS. 15 to 17 are aberration curve diagrams of Example 2, and FIGS. 18 to 20 are Examples. 21 to 23 are aberration curve diagrams of Example 4, FIGS. 24 to 26 are aberration curve charts of Example 5, and FIGS. 27 to 29 are Example 6.
Is an aberration curve diagram of Example 7, FIGS. 30 to 32 are aberration curve diagrams of Example 7, and FIGS. 33 to 35 are aberration curve diagrams of Example 8.

Claims

(57) [Claims]

1. A first lens group having a negative refracting power as a whole from the object side and having a fixed focusing function during zooming, and a positive refracting power as a whole and movable during zooming. It consists of a second lens group and a third lens group that has a positive refracting power as a whole and is movable during zooming. When zooming, the third group is moved so as to draw a convex locus on the image side.
In addition, the second lens group is moved so that the relative distance between the second lens group and the third lens group changes so that zooming is performed while keeping the image position constant, and the following condition (1) is satisfied. Variable magnification lens. (1) −0.54 <B _{II III} <−0.1 However, β _{II III} is a composite image formation magnification of the second lens unit and the third lens unit at the wide-angle end.

2. A variable lens system according to claim 1, wherein at least one surface of the first lens group is an aspherical surface, and the shape is such that the negative refracting power decreases with distance from the optical axis. Double lens.

3. The second lens group includes one or two lenses, and includes an aspherical surface whose positive refracting power decreases as the distance from the optical axis increases, and the aspherical surface satisfies the following condition (7). The variable power lens according to claim 1 or 2, characterized in that (7) │Δ _{x II} │ <0.1h (y = y ₁ ) where Δ _{x II} is the amount of deviation from the reference spherical surface of the aspherical surface, h is the maximum image height, and y ₁ is the marginal ray with an aperture ratio of 2.2. It is the ray height on this surface.

4. The variable power lens according to claim 3, which satisfies the following condition. _{(2) 0.1 <| f W} / f I | <1 (3) 0.1 <| f W / f II III | <1 (4) ν III p> 40 (5) 0.2 <f W / r I n <1.4 However, f _W is the focal length of the entire lens system at the wide-angle end, and f _I is the first
F _{II III} is the combined focal length of the second and third lens groups, ν _{III p} is the Abbe number of at least one positive lens in the third lens group, and r _{I n} is the first lens It is the radius of curvature of the image-side surface of at least one negative lens in the group.